Victor Osimhen has been a speculation for PSG as well. Napoli president Aurelio de Laurentiis made a
statement that PSG could even be the only team to afford him now. Their asking price is believed to be around 150 million euros now. He says that they can evaluate the offer seriously if PSG offer around 200 million euros.
Even if PSG meet only the asking price I don't feel like they are likely to find an opponent in this race at that level. It is all up to whether PSG really see him as priority.
I think Osimhen is a perfect striker for PSG and he will be useful for PSG even that team start a new season with or without Mbappe. With Osimhen, PSG will have a good striker who will bring many goals for their team and more than that, he will be able to support Mbappe (if Mbappe stays) and other players by his readiness to do proactively defense at the frontline.
If anyone needs examples for his readiness to do that, look at his performance in Champions League matches with Leipzig. Even when Napoli led with big goal difference, Osimhen still chased the ball around the box of Leipzig.